Efficient Rotation-Scaling-Translation Parameter Estimation Based on the Fractal Image Model
Abstract
This paper deals with area-based subpixel image registration under the rotation-isometric scaling-translation transformation hypothesis. Our approach is based on parametrical modeling of geometrically transformed textural image fragments and maximum-likelihood estimation of the transformation vector between them. Due to the parametrical approach based on the fractional Brownian motion modeling of the local fragments' texture, the proposed estimator MLfBm (ML stands for "maximum likelihood" and fBm stands for "fractal Brownian motion") has the ability to better adapt to real image texture content compared with other methods relying on universal similarity measures such as mutual information or normalized correlation. The main benefits are observed when assumptions underlying the fBm model are fully satisfied, e.g., for isotropic normally distributed textures with stationary increments. Experiments on both simulated and real images and for high and weak correlations between registered images show that the MLfBm estimator offers significant improvement compared with other state-of-the-art methods. It reduces translation vector, rotation angle, and scaling factor estimation errors by a factor of about 1.75-2, and it decreases the probability of false match by up to five times. In addition, an accurate confidence interval for MLfBm estimates can be obtained from the Cramer-Rao lower bound on rotation-scaling-translation parameter estimation error. This bound depends on texture roughness, noise level in reference and template images, correlation between these images, and geometrical transformation parameters
Keywords
Area-based image registration
Artifacts
Cramer-Rao lower bound (CRLB)
Fisher information
fractional Brownian motion model
Hyperion
hyperspectral imagery
intensity
isometric scaling
Landsat 8
maximum-likelihood estimation (MLE)
mutual-information
Performance
performance limits
registration
rotation
signal-dependent noise
subpixel registration
translation
Origin : Files produced by the author(s)
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